Comet 2006 P1 (McNaught) was a truly spectacular sight throughout the Southern Hemisphere. This image, taken from the European Southern Observatory’s Paranal Observatory in Chile in January 2007, shows the comet and a crescent Moon over the Pacific Ocean. Credit: S. Deiries/ESO, CC BY 4.0
Comets are small, roundish bodies made of dust grains mixed with ice. Most travel along elliptical orbits that occasionally bring them close to the Sun.
The main icy body of the comet is its nucleus. It’s small, generally less than 6 miles (10 kilometers) in diameter. When far from the Sun, comets appear faint because we’re seeing only sunlight reflected off the tiny, frozen nucleus.
